Synthesis of alkyl or aryl pyridazinyl ethers

This paper presents the synthesis of some alkyl or aryl pyridazinyl ethers from 2‐alkyl‐4‐halo‐5‐hydroxy‐and 2‐alkyl‐4,5‐dichloropyridazin‐3(2 H )‐ones or 3,6‐dichloropyridazine. Reaction of 2‐alkyl‐4‐halo‐5‐hydroxypyridazin‐3(2 H )‐ones 1 with 1,2‐dibromoethane or 1,3‐dibromopropane gave the corresponding monopyridazin‐5‐yl ethers 2 and α,ω‐[di(pyridazin‐5‐oxy)]alkanes 3 . Treatment of 4 with 4‐substituted‐phenol afforded 5‐(4‐substituted‐phenoxy)‐2‐(4‐substituted‐phenoxymethyl) derivatives 5 . Reaction of 2‐alkyl‐4,5‐dichloro derivatives 7 with 1 gave the corresponding di(pyridazin‐5‐yl) ethers 8 in good yields. Compound 10 was reacted with catechol to give monopyridazin‐3‐yl ether 11 and/or di(pyridazin‐3‐yl) ether 12 . Also we described the results for the reaction of 2‐alkyl‐4‐chloro‐5‐(4‐substituted‐phenoxy)pyridazin‐3(2 H )‐ones with nucleophiles.